For example, in a semiconductor device in which a light reception element or the like is provided upon the main surface, an electrode pad that is provided near the light reception element may be electrically connected to a connection terminal that is provided upon a circuit board by wire bonding, and the wire and the semiconductor chip may be sealed with transparent resin. In such a semiconductor device in which a semiconductor chip and a connection terminal are connected together by wire bonding, a technique is per se known in which, in order to keep the profile of the semiconductor device low, one end of a wire is ball bonded to the electrode pad of the semiconductor chip, and a loop portion is formed in this wire, this loop portion being continuous from this bonded portion and protruding in the direction opposite to the portion of the wire that is bonded to the connection terminal.
In other words, this loop portion has a turned back portion extending in the opposite direction to the portion of the wire that is bonded to the connection terminal, and this loop portion is squashed down so that a concave portion is formed at the upper central wire portion that is pressed down toward the ball portion that has been created by the bonding process, and moreover so that the lower surface of the central portion of the loop portion contacts another portion of the loop portion that is formed above the ball portion (for example refer to FIG. 5 of Patent Literature #1).